1. Field
Embodiments of the invention relate to electronic systems, and more particularly, to fault protection systems for amplifiers.
2. Description of the Related Technology
Certain amplifiers can be exposed to a fault condition, in which the voltage level of a pin of the amplifier falls outside a range of voltage associated with normal operating conditions. For example, amplifiers can communicate using a ratiometric signaling protocol, in which the amplifier generates an output signal proportional to a measured parameter, such as pressure, temperature, air flow, mass flow, speed, acceleration, fluid level, or the like. The ratiometric signaling protocol can have valid signal ranges defined by a power high supply voltage and a power low supply voltage. For example, a signal may be defined as having a valid signal range within about 10% to about 90% of a voltage difference between the power high and power low supply voltages, with signals falling outside of the valid signal range indicating fault conditions.
A fault condition can arise on a signaling interface for a variety of reasons. For example, fault conditions can be associated with floating power high and/or floating power low supply voltages. Additionally, fault conditions can arise after interface misconnection, such as misconnection of a load resistor or misconnection of the amplifier's power high and power low supply voltage pins, which can lead to overvoltage or undervoltage conditions on the signaling interface. Furthermore, a fault condition can arise from a transient electrical event, or an electrical signal of relatively short duration having rapidly changing voltage and high power. Transient electrical events can include, for example, electromagnetic interference (EMI) and electrostatic discharge (ESD) events, such as those defined by standards sets by various organizations, such as the Joint Electronic Device Engineering Council (JEDEC), the International Electrotechnical Commission (IEC), the Automotive Engineering Council (AEC), and the International Organization for Standardization (ISO).